The intended objects for the loop formation according to this invention include metallic binding bands. Metallic binding bands are formed as illustrated in FIGS. 7 and 8.
A metallic binding band 1 is composed of a binding section 2 wherein a band-shaped steel material cut to a prescribed length has been formed in a ring, a lever 3 wherein a band-shaped steel material of a prescribed length has been welded to the connected overlapping ends 2a of the binding section 2 and formed in a curved shape, and a retaining piece 4 for fixing the lever 3 wherein a band-shaped steel material cut to a prescribed length has been bent into the shape of a U and welded to a prescribed position on the binding section 2, with both ends bending around the outside of the ring formed by the binding section 2.
The metallic binding band 1 is prepared by cutting the binding section 2, lever 3, and retaining piece 4 separately out of a long steel material, processing them appropriately, welding the retaining piece 4 onto the binding section 2, and welding the lever 3 to the overlapped section 2a of both ends of the binding section 2.
However, this method results in a problem that, in welding the lever 3 to the overlapped section 2a of the binding section 2, as shown in FIG. 9, the binding section 2 is flattened or the lever 3 is left flat or deformed from its initial arc curve. It follows that some difficulty is experienced in inserting a hose into the binding section 2 and that force is partially applied in clamping, resulting in deterioration of the hose.
There is sometimes a flash at the end section of the connection side of the lever 3 to the binding section 2. In the presence of such a flash at the end 3a of the lever 3, when the lever 3 is turned over (clamped) about the end 3a of the connecting side of the lever 3 to the binding section 2, there is a possibility that clamping the lever 3 will result in the binding section 2 being cut by the flash at the end 3a of the lever 3.
For these reasons, it has become necessary to aftertreat the formed metallic binding band to make the building section 2 exactly circular and to form the lever 3 into an arc.